This specification relates to predicting user interests.
The Internet provides access to a wide variety of resources, for example, video files, image files, audio files, or Web pages. Search systems are used to help users find resources that may satisfy their informational needs. A search system receives a search query and selects one or more resources in response to receiving the search query. A search query is data that a user submits to a search engine to find resources that satisfy the user's informational needs. The search queries are usually in the form of text, e.g., one or more query terms. The search system selects and scores resources based on their relevance to the search query and on their importance relative to other resources, and provides search results that link to the selected resources ordered according to the scores.
Providers of some search systems provide advertisements with the search results to monetize their services. A prevalent Internet advertising model targets advertisements based on query keywords. The advertisements are sent to the user device to be presented with search results responsive to the query. Some advertising models take into account user search histories on a per-user basis when providing advertisements. For example, some models take into account one of a query history of user queries, a query frequency of user queries, or a category history of user queries to predict a next query or query category for a user. However, each of these models is sensitive to the environment in which a user submits queries and how often a user uses the search service. For example, when a user submits queries in a maps-based interface, the previous queries submitted by the user may not be indicative of the user's current interests. Likewise, when a user submits queries to the search service infrequently, e.g., once a day or even less frequently, the times of the previous queries submitted by the user may not be relevant to the current query.